If you are handy, you can make a tool to pull codes for $4
worth of parts from RS.
I contain the parts in a clear plastic film can so you are able to see the led. Use the removable top to mount the switch. Bring the test leads out a hole in the bottom.
Fits in your hand nicely.

Code retrieval is key on , hold button 2-3 sec., count flashes,
repeat step 1 to continue on to next.
To clear code , hold sw 8-10 sec. after each code .
No flash or 1 flash means no codes stored.
Disconnecting the bat to get rid of the ck eng lite serves you no purpose [ except temp putting the lite out] . You want the code to see why the lite came on.
There are pulse code retrivalinstructions better than these in the archive. Use search eng.
Or any ????? on the tool, you may email me.